An 18-year-old female named Ulindi has now become the first bonobo (Pan paniscus) to have its genome sequenced. Scientists hope that the information gleaned will explain the stark behavioural differences between bonobos and common chimpanzees (Pan troglodytes) and help to identify the genetic changes that set humans apart from other apes.

The genome is published today in Nature. The bonobo is the last extant species of great ape to receive the sequencer’s attentions, following humans (Homo sapiens), chimps, orang-utans (Pongo pygmaeus and Pongo abelii) and gorillas (Gorilla gorilla and Gorilla beringei).

Humans, chimps and bonobos all share a common ancestor that lived about 6 million years ago in Africa, when the human lineage splintered off. By the time that our Homo erectus ancestors were roaming the African savannah 2 million to 1.5 million years ago, populations of the common ancestor of chimpanzees and bonobos had been separated by the Congo River.

Little and probably no interbreeding has occurred since then, says Kay Prüfer, a bioinformatician at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, who led the sequencing study. Comparisons of the bonobo genome and sequences of chimps from various populations showed that chimps living just across the Congo River were no more closely related to bonobos than were populations living as far away as Côte d’Ivoire. That implies that the separation was quick and permanent, says Prüfer.

Once the ancestors of bonobos had been separated from those of chimpanzees, they may have found themselves in a very different ecological world. North of the Congo River, the ranges of chimpanzees and gorillas overlap, so those animals compete for food. But no gorillas live south of the river, so bonobos face much less food competition, says Victoria Wobber, a comparative psychologist at Harvard University in Cambridge, Massachusetts, who has worked with bonobos including Ulindi.

Easy-going apes

In the absence of competition, the ancestors of bonobos may have been free to forage a wider range of foods in large groups, and share the spoils freely. “When food is more consistently available, a lot of the aggression you see in chimps, you don’t need anymore,” says Wobber.

Bonobos also treat sex as casually as a handshake, earning them the nickname “hippie chimps.” The sex is often non-procreative and can occur between pairs of the same sex. Chimps tend to have sex only when females are in estrous. “Instead of resolving their disputes aggressively, maybe they’re resolving them with sex,” says Wobber. And whereas chimpanzee groups are dominated by hyper-aggressive males, bonobo groups are less hierarchical and are often headed by females.

Genetic discrepancies between chimps and bonobos must be involved in these behavioral differences, says Prüfer. But identifying which genetic changes are involved and how they influence behavior will take time.

As a start, Prüfer’s team identified regions of the bonobo genome that differ from those of chimps and that may have evolved in bonobos since the split. Many of these regions contain no genes, while the genomic region that seems to have evolved the fastest in bonobos encodes a microRNA molecule that probably regulates the activity of as-yet unidentified genes.

Prüfer is not dispirited by those results. Any behaviour is influenced by hundreds or even thousands of genes, not one or a handful. “The chance that you flip one trigger and suddenly you’re a bonobo, I don’t think that will happen,” he says.

Family resemblance

By chance, 1.6% of the human genome is more closely related to the bonobo genome than to the chimp genetic code. Knowing which parts of the human genome are shared with other primates can help scientists to work out which bits are not, and identify the sequences that make us unique among apes. “The real benefit of the bonobo genome is being able to narrow down the list,” says Ajit Varki, a biochemist at the University of California, San Diego.

However, the sequence of a single bonobo is not enough, says Varki. Other bonobos may share different genomic regions with humans, and these genes would be missed by relying on a single bonobo sequence. Varki says that researchers are planning to sequence the genomes of dozens more bonobos, chimps and gorillas to fill the gaps.

And Ulindi may not be representative of most bonobos in behaviour, either. Wobber has noticed vast behavioral differences in her work with bonobos, and says that the genomic model of the hippie chimp isn’t a peacenik. Ulindi sometimes lashed out at Wobber. “She’s just a mean bonobo. That’s my own personal experience with her,” says Wobber. “I might have picked a different one to sample.”

Comments (13)

If you consider human kind throughout history those males at the top of the physical rung continued dominating by finding ways to control procreation among the lower groups. As a result, chimp like humans reproducing results in a world fuller of chimps, and soon wars breaks out. Almost every society throughout history has regularly spawned this ultimate violence again and again. That’s why we see some more violent societies today because of controlled top down procreation.

On the other hand, America for a few centuries was such a large open continent whereby those machophiles at the top had a difficult time controlling the masses of reproduction. The result has been a little more civil and sane America for a time. Today however, as a result of improving transportation and communication those same old machophiles at the top are back at their old game of solidifying power by passing one law after the other, until soon, they alone will again dominate procreation. As a result America and the world will again be fuller of chimp like humans and again back at war. Don’t think so, then just keep your eyes and ears on the news. They always continue to pass one law after the other until they have absolute order and power. It’s that same old muscle headed instinct that it will take science to change if mankind don’t become just one more extinct planet in the universe.

Where creating smaller and more powerful weapons in which a few or only one individual could destroy a city. Science will have no choice but to change human nature. It will begin within the next fifty years.

Bill Clinton once gave a long lecture about bonobos, because of their sexual proclivities. Father with daughters, mothers with sons, brothers with sisters, any age group with any other age group. They have no taboos! I know of a lot of bible belt people who would love to save their souls. Oh the humanity of it all. God is gonna come down and smite that Sodom one of these days. Just you wait. You’ll see ! We should hold a telethon, raise up a lot of money and do it for our selves, seeing how God must be busy somewhere else. But he’s watching, and I can tell you personally . He’s told me. A good nuke goes a long way. Such a terrible influence on people. Look away , before your influenced like poor Bill.

I’m a hippie. I’ve got hair down almost to my —-. My Yoga teacher had a chimp. No longer needed for medical experiments, he adopted her. All she wanted to do was to preen me all day, looking for ticks and fleas. She just wanted to fit in, and in chimp society who preens who set social rank. Yea hippies like chimps and chimps like hippies!

There is still differing opinions on whether humans all came from Africa or evolved separately in different regions. But that aside, what has any of this to do with hippies, a term coined and used by the media for anyone with long hair or slightly different tastes to them? Do bonobos like to categorise and label others also? Maybe there’s a gene for it.

The multiple region evolutionary hypothesis sounds like nonsense to me. Separate regions lead to separate species not the same one. How do different species converge into a single one (which we are), pray tell? Has that ever happened? I think some people are just loath to admit that they are related to Africans as a result of their racism and use very convoluted logic to try to find an alternative explanation. The Chinese apparently tried to use genetic sequencing to prove that they evolved from Homo erectus independently from the rest of humanity only to find that they, too, were related to Africans.
The Bonobo studies are important because they show us that we also have the capacity to “make love, not war.” Our continued existence may depend on it.